Various articles of commerce and general use a coating of some kind on surfaces thereof for a specific purpose, such as to prevent corrosion, to reduce abrasion, to reduce contamination or to perform a combination of the three. Discontinuities in a coating are frequently very minute and not readily visible. Since the quality and cost of the coating is dependent on the coating weight and uniformity it is desirable that a means for monitoring these characteristics be employed.
Aircraft surfaces in particular are often coated with a corrosion inhibiting compound (“CIC”), sometimes called a corrosion prevention compound, to preserve the aircraft components and structure. A typical CIC is substantially transparent, and is only apparent to the naked eye when a thick coat is applied, which appears to give a brownish tint to the substrate. But while it is important to achieve adequate coverage of designated surfaces, it may be desirable to use a thin coating to reduce excess weight.
Many techniques have been developed to enable inspection of coated surfaces to ensure adequate coverage. Some coatings employ fluorescent agents to permit inspection of the coated surface using a UV light source. However, since fluorescence is typically a fairly weak effect, high intensity UV light sources are required for reliable detection of inconsistencies in a given circumstance. In addition, many areas requiring protective coatings are not readily accessible and providing UV light in such areas may be difficult or prohibitive. Furthermore, many coated areas requiring inspection have irregular surfaces that require the UV light to be shone from various angles before a determination can be made regarding the adequacy of the coating. The cost of special lighting further disadvantages this solution.
Some current solutions employ cameras to capture images of the coated surfaces, but these systems usually suffer from some of the same limitations as those above. The camera solutions are difficult to use in certain spaces, are often unable to be used on remote surfaces, and are costly and time-consuming. As a result, there remains a need for an improved system and method for applying and inspecting a protective coating.